Merge tag 'staging-4.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging fixes from Greg KH:
 "Here are three staging driver fixes for 4.16-rc6

  Two of them are lockdep fixes for the ashmem driver that have been
  reported by a number of people recently. The last one is a fix for the
  comedi driver core.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: android: ashmem: Fix possible deadlock in ashmem_ioctl
  staging: comedi: fix comedi_nsamples_left.
  staging: android: ashmem: Fix lockdep issue during llseek

Author: torvalds

drivers/staging/android/ashmem.c

@@ -326,24 +326,23 @@ static loff_t ashmem_llseek(struct file *file, loff_t offset, int origin)
 	mutex_lock(&ashmem_mutex);
 
 	if (asma->size == 0) {
-		ret = -EINVAL;
-		goto out;
+		mutex_unlock(&ashmem_mutex);
+		return -EINVAL;
 	}
 
 	if (!asma->file) {
-		ret = -EBADF;
-		goto out;
+		mutex_unlock(&ashmem_mutex);
+		return -EBADF;
 	}
 
+	mutex_unlock(&ashmem_mutex);
+
 	ret = vfs_llseek(asma->file, offset, origin);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	/** Copy f_pos from backing file, since f_ops->llseek() sets it */
 	file->f_pos = asma->file->f_pos;
-
-out:
-	mutex_unlock(&ashmem_mutex);
 	return ret;
 }
 
@@ -702,16 +701,14 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd,
 	size_t pgstart, pgend;
 	int ret = -EINVAL;
 
+	if (unlikely(copy_from_user(&pin, p, sizeof(pin))))
+		return -EFAULT;
+
 	mutex_lock(&ashmem_mutex);
 
 	if (unlikely(!asma->file))
 		goto out_unlock;
 
-	if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) {
-		ret = -EFAULT;
-		goto out_unlock;
-	}
-
 	/* per custom, you can pass zero for len to mean "everything onward" */
 	if (!pin.len)
 		pin.len = PAGE_ALIGN(asma->size) - pin.offset;

drivers/staging/comedi/drivers.c

@@ -475,8 +475,7 @@ unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
 	struct comedi_cmd *cmd = &async->cmd;
 
 	if (cmd->stop_src == TRIG_COUNT) {
-		unsigned int nscans = nsamples / cmd->scan_end_arg;
-		unsigned int scans_left = __comedi_nscans_left(s, nscans);
+		unsigned int scans_left = __comedi_nscans_left(s, cmd->stop_arg);
 		unsigned int scan_pos =
 		    comedi_bytes_to_samples(s, async->scan_progress);
 		unsigned long long samples_left = 0;